Polymer optical fibers have been expected to be an optical transmission device to be used in local area networks (LAN) and optical sensors because of their favorable characteristics of processability, low cost and ease of handling. A sufficiently wide bandwidth is obtainable with the polymer optical fibers because both GI and SM (single mode) types can be manufactured today. However, their drawback is that the transmission loss is greater than that of quartz-base optical fibers. It seems possible to reduce the loss by deuteration and fluorination of polymers, but such reduction effects may be limited. For this reason, people are expecting development of a higher performance amplifier which is adaptable to optical fiber systems as a means to recover such loss. This is because the transmission distance of polymer optical fibers is approximately 200 meters, and all optical LANs which seem necessary in the future can be constructed with polymer optical fibers if a polymer optical fiber amplifier is successfully developed. Under these circumstances, development of a polymer optical fiber amplifier is much expected.
No report, however, has ever been published regarding such a fiber amplifier.
The present invention has been performed against the above condition. The objective of the present invention is to offer a new polymer optical fiber amplifier which improves the problem of transmission loss of conventional optical fibers, and significantly enhances the performance of a polymer optical fiber system by the use of its excellent amplifying operation.